The invention relates to pump assemblies or aggregates in general, and more particularly to improvements in assemblies wherein a preferably glandless motor drives the impeller of a centrifugal pump. Such pump assemblies can be used for circulation of fluids which are maintained at an elevated pressure and/or temperature, for example, to recirculate water in boiling water reactors.
It is already known to drive a vertically mounted recirculating pump by a glandless motor whose output member rotates the impeller of the pump. It is also known to provide in such assemblies a barrier serving to interfere with the transfer of heat from the pump to the motor which latter is normally mounted at a level below the pump. A drawback of presently known assemblies of the above outlined character is the complexity of heat barrier, high initial and maintenance cost, and excessive transfer of heat between the pump and motor.